I am building an android app that needs to communicate over a WiFi network that will not have any internet access. The problem is that even when the WiFi is connected androi
Could you try and set the global setting captive_portal_detection_enabled to 0 (false).
What's actually happening is that by default, everytime you connect to a wifi, the FW will test against a server (typically google) to see if it's a captive wifi (needs login). So if your wifi is not connected to google, this check will fail. After that, the device knows that wifi has no internet connection and simply will not autoconnect to it.
Setting this setting to 0, will avoid this check.
Programatically:
Settings.Global.putInt(getContentResolver(), Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 0);
Edit: You may need to use the string "captive_portal_detection_enabled" directly, instead of the constant that's not visible depending on Android version.